In audio output applications, output amplifier device overheating often leads to increased harmonic distortion, and can potentially cause a catastrophic failure of an end product. To address this problem, designers have traditionally mounted a separately packaged bias protection or compensation device to a heat sink in close proximity to a separately packaged output amplifier device. One problem with this approach occurs because a period of time must pass before thermal equilibrium is achieved. This period of time may be as long as thirty minutes, and is referred to as “warm-up” time. Also, this approach is susceptible to moisture aging problems and mechanical contact degradation. Additionally, many designers design the circuits to slightly under bias the output amplifier to reduce the potential for thermal runaway. Both of these approaches take away from the true high fidelity performance of the output amplifier device.
Accordingly, a need exists for a structure and method of manufacture to more efficiently and accurately provide bias protection or compensation for output amplifier devices, and that overcome the deficiencies of the prior art.